91871489 has 2 divisors, whose sum is σ = 91871490. Its totient is φ = 91871488.

The previous prime is 91871473. The next prime is 91871537. The reversal of 91871489 is 98417819.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 88981489 + 2890000 = 9433^2 + 1700^2 .

It is a cyclic number.

It is not a de Polignac number, because 91871489 - 2⁴ = 91871473 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (91871459) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45935744 + 45935745.

It is an arithmetic number, because the mean of its divisors is an integer number (45935745).

Almost surely, 2^91871489 is an apocalyptic number.

It is an amenable number.

91871489 is a deficient number, since it is larger than the sum of its proper divisors (1).

91871489 is an equidigital number, since it uses as much as digits as its factorization.

91871489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 47.

The square root of 91871489 is about 9584.9616066002. The cubic root of 91871489 is about 451.2254482848.

The spelling of 91871489 in words is "ninety-one million, eight hundred seventy-one thousand, four hundred eighty-nine".